Inhibition of drug transport by genistein in multidrug-resistant cells expressing P-glycoprotein.

Article Details

Citation

Copy to clipboard

Castro AF, Altenberg GA

Inhibition of drug transport by genistein in multidrug-resistant cells expressing P-glycoprotein.

Biochem Pharmacol. 1997 Jan 10;53(1):89-93.

PubMed ID

8960067 [ View in PubMed

]

Abstract

It has been claimed that the flavonoid genistein could be used to distinguish multidrug-resistant tumors expressing the multidrug resistance-associated protein (MRP) from those expressing P-glycoprotein (Pgp). Genistein would be block drug transport by MRP without affecting Pgp-mediated drug transport. However, we found that exposure to 200 microM genistein elicited an elevation in intracellular accumulation of rhodamine 123 (R123) and daunorubicin (DNR) in Pgp-expressing cell lines. Genistein inhibited R123 efflux in a rapidly reversible manner (ca. 2 min). The flavonoid also decreased photoaffinity labeling of Pgp by [3H]azidopine, a Pgp substrate. The present results show that genistein interacts with Pgp and inhibits Pgp-mediated drug transport. Hence, genistein cannot be used in simple assays to distinguish MRP- and Pgp-expressing cells.

DrugBank Data that Cites this Article

Drug Transporters

Drug	Transporter	Kind	Organism	Pharmacological Action	Actions
Genistein	P-glycoprotein 1	Protein	Humans	Unknown	Inhibitor	Details